The Anacortes refinery, owned by Marathon Petroleum Corporation, has recently applied for a U.S. utility patent for its innovative use of ammonia from a specific refinery waste stream to reduce emissions. This project has been recognized by the Northwest Construction Consumer Council as the best private-sector project of 2023 under $10 million.
The initiative at the Anacortes refinery focuses on reducing nitrogen oxides (NOx) emissions, which is a significant contributor to air pollution. By incorporating selective non-catalytic reduction technology, the refinery achieved a remarkable 31 percent reduction in NOx emissions, equivalent to 321 tonnes per year. This reduction is comparable to removing 180,000 light-duty vehicles from the road annually.
MPC’s Process Engineer, David Rudd, explained that computational fluid dynamics modeling was used to optimize chemical reactions that effectively destroy NOx emissions. The project utilized ammonia from a specific refinery waste stream, which is believed to be a first in the refining industry.
The project primarily targeted one of the carbon monoxide (CO) boilers in the Anacortes refinery’s fluid catalytic cracking unit. Infrastructure modifications were made to redirect ammonia from another refining process and inject it into the CO boiler’s firebox. This allows the ammonia to react with oxygen and NOx, resulting in the production of nitrogen and water vapor, thus reducing emissions.
The innovative approach of using ammonia from a specific refinery waste stream has formed the basis of the refinery’s application for a U.S. utility patent, which is currently pending. This recognition by the NWCCC not only acknowledges the project’s innovation but also its adherence to safety, timeliness, and budget efficiency.
MPC’s Engineering Supervisor, Zac Nightingale, highlighted the project’s cost-effectiveness compared to other emissions-reduction methods, stating that similar methods could cost 10 to 20 times more to implement. The successful completion of the project was a result of collaboration between the refinery’s technical services and environmental departments, as well as contractors providing engineering support, instrumentation, electrical services, and construction.
Looking ahead, the Anacortes refinery is considering plans to install a similar SNCR injection system on the second CO boiler in the future. This commitment to continuous improvement and emissions reduction demonstrates MPC’s dedication to environmental sustainability and responsible refining practices.
For more information visit www.marathonpetroleum.com
